Antioxidant composition comprising a synergistic mixture of a phenol, amine and sulfone

ABSTRACT

An antioxidant composition comprising a mixture of an oil soluble phenol, an oil soluble amine and a long chain alkylthioethyl sulfone compound and oxidizable organic materials, particularly petroleum oil containing such antioxidant composition.

Beiswanger et al.

ANTIOXIDANT COMPOSITION COMPRISING A SYNERGISTIC MIXTURE OF A PHENOL, AMINE AND SULFONE Inventors: John P. G. Beiswanger, Audubon;

Assadullah Nassry, Bethlehem, both of Pa.

Assignee: GAF Corporation, New York, NY. Filed: Dec. 1, 1971 Appl. No.: 203,848

References Cited UNITED STATES PATENTS 12/1940 Dewey 252/52 A [451 Oct. 1, 1974 2,687,378 8/1954 Goldschmidt et a1. 252/51.5 R 2,809,164 10/1957 Pruett 252/51.5 R 3,173,871 3/1965 Elliott 252/5l.5 R 3,250,713 5/1966 Reinis 252/51 5 R 3,407,140 10/1968 Chiddix et a1. 252/47.5

Primary Examiner--W. Cannon Assistant ExaminerW. Cannon Attorney, Agent, or Firm-Walter C. Kehm; Samson B. Leavitt [57] ABSTRACT An antioxidant composition comprising a mixture of an oil soluble phenol, an oil soluble amine and a long chain alkylthioethyl sulfone compound and oxidizable organic materials, particularly petroleum oil containing such antioxidant composition.

9 Claims, No Drawings ANTIOXIDANT COMPOSITION COMPRISING A SYNERGISTIC MIXTURE OF A PHENOL, AMINE AND SULFONE This invention relates to antioxidant compositions which may be used for stabilization of organic compounds, particularly petroleum oil which tends to deteriorate in storage or in use due to oxidation. It is well known that certain organic materials such as lubricating oils, fuels, edible oils, elastomers, plastics, synthetic resins, etc., are adversely affected by oxygen resulting in the formation of gums, discoloration, loss of physical properties such as tensile strength for resins, or elasticity for elastomers, loss of potency, rancidity and/or odor. Over a period of years there has been considerable research directed to remedying the poor resistance of these materials toward oxidation. A number of patents have issued which are directed to the purpose of preventing oxidative deterioration by providing a means for extending the useful life of these materials by using various types of oxidation inhibitors. An object of the present invention is to provide an antioxidant composition which results in a total antioxidant effect that is greater than the sum of the effects of each ingredient thereof taken independently.

A specific object of this invention is to provide an antioxidant composition comprising a phenolic antioxi dant, an amine and a sulfone compound.

A further object is to provide new stable compositions of matter by incorporating these novel antioxidant compositions into organic materials such as synthetic resins, plastics, fuels, elastomers, lubricating oils, turbine oil, motor oil and other materials susceptible to deterioration due to oxygen or related degradation processes.

Other objects of this invention will become more apparent as the disclosure proceeds.

The above objects may be readily accomplished by the preparation and use of a composite antioxidant composition comprising a sulfone compound, an amine and phenolic antioxidant. While the use of phenolic compounds as antioxidants is not new, it has now been found that the addition of a sulfone compound and amine to said phenolic antioxidant results in a surprising and totally greater effectiveness. While one would assume that the combination would result in an effectiveness that was equal to the arithmetical sum of the individual separate effects, it has now been discovered that the combined effectiveness is unexpectedly greater than the arithmetic sum of the three. In other words, by the addition of a sulfone compound to an amine and a phenolic compound a synergistic effect has been obtained.

In U.S. Pat. No. 3,407,140 the synergistic effect ofa sulfone compound and a phenolic compound as an antioxidant combination has been disclosed. In accordance with the invention it has been found that the latter synergistic effect is still further increased by the addition of an amine.

More particularly, the instant invention may be defined as an antioxidant composition consisting essentially of a phenolic antioxidant, amine and a sulfone butylphenol); polyhydric phenols such as catechol, resorcinol and hydroquinone; cresols such as 2,6-di-tbutyl-4-methoxy phenol, 4',4' methylene bis (6-t-butylo-cresol); 4,4-thiobis (6-t-butyl-o-cresol); dihydroxyanthraquinones such as quinizarin, 2 n-dodecyl quinizarin; naphthol, and alkylated naphthol.

Typical examples of amines useful as components in the antioxidant synergistic system of the invention are N-arylnaphthylamines such as N-phenyl-a or ,B-naphthylamine, alkylated arylamines such as 4,4-dioctyldiphenyl amine; aliphatic amines, in which the carbon chain length is between C C- heterocyclic amines such as phenothiazine, quinoline, imidazolines, triazines, aromatic amines such as n-alkylated-aniline, and long chain amines ethoxylated with an amount of ethylene oxide which is low enough to maintain solubility of the ethoxylated amine in oil.

As sulfone component, there are suitable the long chain alkylthioethyl sulfone compounds such as B-t-butylthioethylsulfone, B-n-dodecylthioethyl-ndodecyl sulfone, B-t-dodecylthio-B'-t octylthiodiethyl sulfone, B-n-octadecylthioethyl-n-octadecyl sulfone, B-t-dodecylthioethyl-t-dodecyl sulfone, B-cyclohexylthioethyl cyclohexyl sulfone, bis-B-b-clodecylthioethyl sulfone, bis-B-t-octylthioethyl sulfone, bis-,B-n-hexadecylthioethyl sulfone, bis-B-t-butylthioethyl-t-butyl sulfone and bis-B-t-octylthioethyl sulfone. Bis-B-t-dodecylthioethyl sulfone is an example of a preferred sulfone for use in preparing the antioxidant composition of the invention.

The sulfones are not new materials and their preparation is well known and has been described for instance in U.S. Pat. No. 3,407,140.

The amount of phenol, amine and sulfone, compounds present in the synergistic antioxidant composition of this invention is not critical for it is obvious that a different ratio may be optimum in each application. However, the ratios will fall within the following ranges.

Component Broad Range Preferred Range Sulfone 0.025 5% 0.05 0.1% Phenol 0.025 5'7, 0.05 0.5 7, Amine 0.025 0.564 0.05 0.1%

The novel antioxidant compositions of this invention find utility in a large variety of applications that deal lates, suberrates, azelates, sebacates, esters from polyols such as pentaerythritol, trimethylol propane, sorbitol, alkyl esters of aliphatic monocarboxylic acids such as lauric, oleic, palmitic, stearic and behenic acids. Other lubricants include silicone lubricants such as 3 4 polysiloxane oils and greases of the type of polyalkyl, 5.00 grams 01' u 1.0 solution 0121 di-bhutyl phenol in Shell polyarylt polyalkoxy polyaryoxy Such as polydime- 5.00 grams ltil' /r ilngllon o1 his-p-t-dodecylthioethyl thoxyphenoxy siloxane, silicate ester oils such as tet- WU m ita ti sh cllum ijlevfitrnlloil I m I i raalkoxy and tetraayloxysilanes and halogen substig ,;;,,",,';,5}, p a tuted siloxanes and the like as well as fluorocarbon lu- 5 grams r ShclhNcutml Oil bricants such lubricants such as (CF CFCl),, where 5000 n g zgggzfig g Such as This was then shaken at room temperature.

A sample composed of 50g petroleum 011 containing 0 the antioxidant and ml of distilled water was intro- JL l0 duced into a rotary bomb and the induction period of the oil sample determined. The results are set out in e; Table I which follows.

wherein R, R and R each represent hydrogen, phe- EXAMPLE 2 nyl, alkylphenyl, or an alkyl radical such as butyl, octyl, lauryl, oleyl, palmityl, and the like, can also be pro- Oils samples containing 0.1% bis-B-t-dodecylthioethtected in accordance with the invention, ylsulfone, O. 1% 2,6 di-t-butyl-p-cresol, O. 1% dioctyl di- Other lubricants include synthetic base greases ph nylamine were prepared. formed by mixing a soap with an oil, soaps derived from Then a 99.7% Shell 100 Neutral Oil was prepared by animal, vegetable, fats, fatty acids, wool grease, rosin introducing into a bottle: or petroleum acids, for instance lead oelate, lithium stearate and the like.

Fuels that y be protected this invention include 5.00 grams 1.0% solution 01'2,6 di-t-hutyl-p-cresol in ell 100 Neutral Oll gasoline, Jet fuel, diesel fuel, kerosme and fuel 011, cm 5.00 grams ofa 1.0% solution of bis-B-t-dodecylthioethyl sulfone in Shell 100 Neutral Oil The novel synergistic antioxidant composition of this grams g gg fil sazrs dphenylum'nc invention may be added to the organic material that 18 35.00 grams of Shell 100 Neutral 00 to be preserved in any manner. For example, the anti- 5000 grams Weightoxidant composition comprising the three components may be diluted with any suitable mutual solvent prior Thls was shaken at P 'f f to use or added without dilution directly to the material Sample 50 g of test 011 cohtafhlhg the antioxidant to be protected. Moreover, the ingredients that is sulas Just flescnbed and 5 m] of dlstlhed water was then fone compound, amine and phenolic compound of the Pl m a rotary b and the induction Period of the antioxidant Composition may be added Separately to 011 sample determined. The results are set out in Table the material that is to be protected. Examples of suit- 1 which able mutual solvents are propylene glycol, glycerine, Addltlthlal Oll Samples Containing the three p glycerides, liquid fats, purified mineral oil, xylene, noheht ahtloxldaht Systems were P p in the Same nylbenzene, ethylacetate, butylacetate, methylisobumanner as described in connection with Examples 1 tylketone and the like. and

The following examples are given in order to in Table 1 which follows sets out the induction periods trate the invention, such examples are not however to of the oils containing 0.05-0.1% N-phenyl-abe taken as limiting or otherwise imposing any restricnaphthylamine, 0.05-0. 1% 2,6 di-t-butylphenol and tions on the invention. 0.05O.1% bis-B-t-dodecylthioethylsulfone.

Table 1 Induction Periods 2,6 di-t-butylphenol, N-phenyl-a-naphthylamine and bis-B-t-dodecylthioethylsulfone Additive 2,6 di-t-butyl phenol .1 0 .1 O .05 O .05 0.1

N-phenyl-a-naphthylamine 0 .l .1 0 0 0 .05 0

bis-B-t-dodecy1thioethyl- 0 0 .1 .1 0 .05 .05 0.1

s fone Induction Period, Min. 131 183 545 37 78 32 300 225 EXAMPLE l The induction period of the oil containing 0.1% 2,6

An antioxidant composition was prepared consisting of 0.1%, 2,6 di-t-butylphenol, 0.1% bis-,B-tdodecylthioethylsulfone and 0.1% phenyl-anaphthylamine.

In order to demonstrate the increased antioxidant protection provided by this antioxidant composition for a lubricating oil, the standard rotary bomb oxidation Test time (ASTM D2272-64%) was carried out as follows:

99.7% Shell 100 Neutral Oil then was prepared by introducing into a bottle:

inaahthxlamias vidual oil samples. This larger than expected increase in induction period shows that bis-B-t-dodecylthioethylsulfone acts in a synergistic manner when it is used in combination with 2,6, di-t-butyl phenol and phenyl-adiphenylamine, and 0.1% 2,6 di-t-butyl phenol +0.l%

dioctyl diphenylamine 0.1% bis-,B-t-dodecylthioethylsrefsms- Table 2 The induction period of the oil sample containing 0.1% 2,6 di-t-butyl-p-cresol is 65 minutes. The induction period of the oil sample containing 0.1% phenyl-anaphthylamine is 183 minutes and the induction period of the oil sample containing 0.1% bis-B-t-dodecylthioethyl-sulfone is 37 minutes. The sum of the individual induction periods of the oil samples containing 0.1% 2,6 di-t-butyl-p-cresol and 0.1% bis-B-t-dodecylthioethyl-sulfone to this oil increases the induction period to 578 minutes. An increase of 330 minutes. This'large increase in induction time shows the synergistic qualities of bis-B-t-dodecylthioethylsulfone when it is used in combination with 2,6 di-t-butyl-p-cresol and N-phenyl-a-naphthylamine. W H

In Table 4 there is set out the induction periods for oils containing 0. 1% 2,6 di-t-butyl-p-cresol, 0.1% dioctyl diphenylamine, and 0.1% 2,6 di-t-butyl-p-cresol 0.1% dioctyl diphenylamine 0.1%

Induction Periods 2,6 di-t-butyl phenol, dioctyl diphenylamine and bis-B-t-dodeeylthioethylsulfone.

The induction period of the oil sample containing 01% 2,6 di-t-butylphenol is 131 minutes The induction period of the oil sample containing 0.1% dioctyl diphenylamine is 33 minutes. The induction period of the oil sample containing 0.l% bis-B-t-dodecylthioethylsulfone is 37 minutes. The sum of these three individual induction periods is 201 minutes. However, the induction period for an oil sample containing all three materials in the same concentrations is 363 minutes. This is an increase of 162 minutes in induction period.

The larger than expected increase in induction period obtained by the addition of bis-,B-t-dodecylthioethylsulfone to the oil is evidence that this material performs as a synergist when used in combination with 2,6 di-t-butylphenol and dioctyl diphenylamine.

In Table 3, there is shown the induction periods for oils containing 0.1% 2,6 di-t-butyl-p-cresol, 0.1% n-phenyl-a-naphthylamine, and 0.1% 2,6 di-t-butyl-pcresol +0. 1% n-phenyl-a-naphthylamine 0.1% bis-B- t-dodecylthioethylsulfone.

Table 3 Table 4 Induction Periods of Oils Containing 0.1% 16 di-t-butyLp-cresol,01% dioctyl diphenylamine and 0. 1'7! bis-,B-tdodecylthioethylsulfone Additive Percent Additive in Oil ().l'71 2,6 di-tbutyl-p cresol .l (l .l 0 0.1% dioctyl diphenylamine .l .l 0.1'71 bis-B-t-dodecylthioethylsulfone I) 0 l .l Induction Period, Min

Induction Periods 2,6 dit-butyl p-cresol, dioctyl diphenylamine and bis-B-t-dodecylthioethylsulfone Additive Percent Additive in Oil 01% 2,6 di-t-butyl-p-cresol .1 O 1 O 0.1% N-phenyl-a-naphthylamine 0 .l l 0 0.l% bis-B-t-dodecylthioethyl-sulfone 0 O .l .1 Induction Period, Min. I83 578 37 than the sum of the three induction periods for the three individual oils.

This increase of l25 minutes in induction period obtained as a result of adding 0.1% bis-B-t-dodecylthioethylsulfone to the oil samples containing 0.1% 2,6 di-tbutyl-p-cresol and 0.1% dioctyl diphenylamine demonstrates the synergistic activity of bis-B-t-dodecylthioethylsulfone when used in combination with the other two additives.

What is claimed is:

1. An antioxidant composition consisting essentially of a phenolic antioxidant selected from the group consisting of M-, and p-cresol, 2,4-di-t-butylphenol, 4- ,4-bis(2,6-di-t-butylphenol), 4',4'-methylene bis-(2,6-di-t-butylphenol), catechol, resorcinol, hydroquinone, 2,6-di-t-butyl-4-methoxyphenol, 4',4'- methylene bis-(6-t-butyl-O-cresol), 4,4-thiobis-(6-tbutyl-o-cresol), quinizarin, 2-n-dodecyl quinizarin and naphthol, and amine selected from the group consisting of N-phenyl-a-naphthylamine, N-phenyl-B- naphthylamine, and 4,4'-dioctyl-diphenyl amine, and a sulfone compound selected from the group consisting of bis-B-t-dodecylthioethyl sulfone, ,B-t-butylthioethylsulfone, [3-n-dodecylthioethyl-n-dodecyl sulfone, ,B-tdodecylthio-B'-t-octylthiodiethyl sulfone, B-noctadecylthioethyl-n-octadecyl sulfone, B-t-dodecylthioethyl-t-dodecyl sulfone, B-cyclohexylthioethyl cyclohexyl sulfone, bis-B-b-dodecylthioethyl sulfone, bis-B-t-octylthioethyl sulfone, bis-B-n-hexadecylthioethyl sulfone, bis-B-t-butylthioethyl-t-butyl sulfone and bis-B-t-octylthioethyl sulfone wherein the ratio of phenolic antioxidant to sulfone to amine compound lies within the range of l 100: l 100: l 100.

2. An antioxidant composition according to claim 1 consisting essentially of a phenol antioxidant, an amine and a sulfone compound wherein the ratio of phenolic antioxidant to sulfone to amine compound lies within the range of l 20: l 10: l 2.

3. An antioxidant composition according to claim 1 consisting essentially of 2,6 di-t-butyl-phenol, N-phenyl-a-naphthylamine and bis-B-t-dodecylthioethylsulfone.

4. An antioxidant composition according to claim 1 consisting essentially of 2,6 di-t-butylphenol, 4,4-dioctyldiphenylaminc and bis-,8-t-dodecylthioethylsulfonc.

5. An antioxidant composition according to claim 1 consisting essentially of 2,6 di-t-butyl-p-cresol, dioctyldiphenylamine and bis-B-t-dodecylthioethylsulfone.

6. An organic hydrocarbon material susceptible to oxidative deterioration selected from the group consisting of hydraulic fluids, automotive transmission fluids, transformer oils, turbine oils, metal working oils, gear oils, lubricating oils, petroleum waxes, greases, gasoline, diesel fuel, glass annealing oils, natural fats and oils, hydrogenated fats and oils, soaps derived from monocarboxylic acids and polybasic acids, and polyalkylene glycol lubricants protected against such deterioration by the inclusion therein of a small antioxidant quantity of an antioxidant composition as defined in claim 1.

7. The composition of claim 6 wherein the organic hydrocarbon material is a lubricating oil.

8. The composition of claim 6 wherein the organic hydrocarbon material is a hydraulic fluid.

9. The composition of claim 6 wherein the organic hydrocarbon material is a liquid fuel. 

1. AN ANTIOXIDANT COMPOSITION CONSISTING ESSENTIALLY OF A PHENOLIC ANTIOXIDANT SELECTED FROM THE GROUP CONSISTING OF O-, M-, AND P-CRESOL, 2,4-DI-T-BUTYLPHENOL, 4'',4''-BIS(2,6-DI-TBUTYLPHENOL), 4'',4''-METHYLENE BIS(2,6-DI-T-BUTYLPHENOL), CATECHOL, RESORCINOL, HYDROQUINONE, 2,6-DI-T-BUTYL-4METHOXYPHENOL, 4'',4''-METHYLENE BIS(6-T-BUTYL-O-CRESOL), 4,4-THIOBIS-(6-T-BUTYL-O-CRESOL), QUINIZARIN, 2-N-DODECYL QUINIZARIN AND NAPHTHOL, AND AMINE SELECTED FROM THE GROUP CONSISTING OF N-PHENYL-A-NAPHTHYLAMINE, N-PHENYL-BNAPHTHYLAMINE, AND 4'',4''-DICOTYL-DIPHENYL AMINE, AND A SULFONE COMPOUND SELECTED FROM THE GROUP CONSISTING OF BIS-B-T-DODECYLTHIONETHYL SULFONE, B-T-BUTYLTHIOETHYLSUFONE, B-N-DODECYLTHIOETHYL-N-DODECYL SULFONE, B-T-DODECYLTHIO-B''-TOCTYLTHIODIETHYL SULFONE, B-N-OCTADECYLTHIOETHYL-N-OCTADECYL SULFONE, B-T-DODECYLTHIOETHYL-T-DODECYL SULFONE, B-CYCLOHEXYLTHIOETHYL CYCLOHEXYL SULFONE, BIS-B-B-DODECYLTHIOETHYL SULFONE, BIS-B-T-OCTYLTHIOETHYL SULFONE, BIS-B-N-HEXADECYLTHIOETHYL SULFONE, BIS-B-T-BUTYLTHIOETHYL-T-BUTYL SULFONE AND BIS-B-T-OCTYLTHIOETHYL SULFONE WHEREIN THE RATIO OF PHENOLIC ANTIOXIDANT TO SULFONE TO AMINE COMPOUND LIES WITHIN THE RANGE OF 1 - 100:1 -
 100. 2. An antioxidant composition according to claim 1 consisting essentially of a phenol antioxidant, an amine and a sulfone compound wherein the ratio of phenolic antioxidant to sulfone to amine compound lies within the range of 1 - 20: 1 - 10: 1 -
 2. 3. An antioxidant composition according to claim 1 consisting essentially of 2,6 di-t-butyl-phenol, N-phenyl- Alpha -naphthylamine and bis- Beta -t-dodecylthioethylsulfone.
 4. An antioxidant composition according to claim 1 consisting essentially of 2,6 di-t-butylphenol, 4,4''-dioctyldiphenylamine and bis- Beta -t-dodecylthioethylsulfone.
 5. An antioxidant composition according to claim 1 consisting essentially of 2,6 di-t-butyl-p-cresol, dioctyldiphenylamine and bis- Beta -t-dodecylthioethylsulfone.
 6. An organic hydrocarbon material susceptible to oxidative deterioration selected from the group consisting of hydraulic fluids, automotive transmission fluids, transformer oils, turbine oils, metal working oils, gear oils, lubricating oils, petroleum waxes, greases, gasoline, diesel fuel, glass annealing oils, natural fats and oils, hydrogenated fats and oils, soaps derived from monocarboxylic acids and polybasic acids, and polyalkylene glycol lubricants protected against such deterioration by the inclusion therein of a small antioxidant quantity of an antioxidant composition as defined in claim
 1. 7. The composition of claim 6 wherein the organic hydrocarbon material is a lubricating oil.
 8. The composition of claim 6 wherein the organic hydrocarbon material is a hydraulic fluid.
 9. The composition of claim 6 wherein the organic hydrocarbon material is a liquid fuel. 